1. Field of the Invention
The present invention relates to a shoe sole for spiked track-and-field athletic shoes used mainly in track events.
2. Description of Related Art
Generally, track-and-field athletic shoes used for track events are fitted with spikes only on the forefoot portion of the sole.
While there are many innovations being made by the various manufacturers, the spikes generally have been arrayed on the sole throughout the entire forefoot portion.
Particularly, in recent years, effort has been made to attach as many spikes as possible within the 11 spikes which is permitted under event regulations, in order to exhibit greater kick power on so-called all-weather tracks which employ a synthetic resin paving material.
In doing so, there are known track-and-field athletic shoes which focus on the load path, which is how the bodily weight acts on the shoe soles during running action, and place spikes on this load path. However, such shoes as these have spikes arrayed throughout the sole area, and in this respect, are no different to the conventional items.
Arraying spikes through the sole region leads to increased weight of the spikes, and also leads to inhibited flexibility of the shoe sole due to the shoe sole being thickened.
When the force which acts during actual running is analyzed from a bio mechanical perspective, it has become clear that the conventional idea of attaching as many spikes as regulations will allow to the sole of the shoes in order to obtain greater kick force, was fundamentally mistaken.
The excessive spikes attached to the shoe sole not only hang up on the track against the intentions of the runner, thereby obstructing natural movement of the legs, but also may decrease kick power in some cases.